Aircraft Siblings: Boeing Jets Built for Both Commercial and Military Use

The P-8A Poseidon is extremely recognizable given its similarity to the Boeing 737 (Photo: Boeing)

While it has become easy to notice a Boeing 737 or Airbus A330 given its popularity with airlines, some might not know that the same production line that produced a Southwest Airlines 737-800 produced a military model of the same jet. In this two-part series, we will look into several commercial aircraft with military siblings. We will ignore VIP transports like the VC-25 and Boeing 777 VIP, as most political figures use a modified commercial airplane to fly around.

Boeing 367

Even though the Boeing 707 receives the love of being the first successful jet-powered commercial aircraft, the prototype of the Boeing 367 has received much attention in the military world. From the Boeing 367’s design would come the X-135 military models, which would soon become the base for multiple military variants.

The most popular version is the KC-135 Stratotanker, which operates as an air refueler for the United States, France, Turkey, Chile, and Singapore. The tanker has a range of 9,700 nautical miles and can carry 83,000 pounds of fuel. The airframe comes equipped with a single boom on the rear of the airplane for refueling aircraft.

The Boeing 367 has also seen significant use for information and data collection with the creation of the C-135 Stratolifter. Most of these variants, including the OC-135 Open Skies and EC-135 are utilized for telemetry and observation, and have special equipment installed to measure either weapons or weather.

In total, over 800 military Boeing 367s have been delivered with some of these features, specifically the KC-135 Stratotanker and RC-135 reconnaissance aircraft still being used around the world.

Boeing 707

Although the Boeing 707 was more commercially viable, the Boeing 367 won out in terms of military styles. However, there are some Boeing 707 military versions that are still being used today.

The most popular aircraft that was based off the Boeing 707 was the Boeing E-3 Sentry. The aircraft prioritizes airborne early warning and is commonly noted for its large radar dish on top of the rear of the fuselage. In total over 60 aircraft were delivered to France, NATO, the U.S. and Saudi Arabia, with most of these aircraft still in use.

The E-3 is based on 707 design elements (Photo: Boeing)

While the E-3 Sentry sold over 60 models, nothing else would come close. The Boeing E-6 Mercury airborne command center has seen use with the United States since the mid-1980s, but only 16 aircraft were made and are still used at Tinker Air Force Base. The other model was another airborne command center with the Boeing E-8 Joint STARS. The Joint STARS featured upgraded systems from Northrop Grumman, and all 17 aircraft made are still in use with the United States.

Boeing 737

The Boeing 737’s most popular military airframe is actually its newest. The Boeing P-8 Poseidon is based on the Boeing 737-800 and focuses on anti-surface warfare for both land and sea. The aircraft has seen use by the United States, India and Australia, with Boeing having delivered 59 aircraft since its launch in 2009.

The other version of the aircraft is the Boeing 737 AEW&C. The AEW&C, which stands for ‘airborne early warning and control’, entered service in 2004 with Australia, Turkey, and South Korea. The aircraft is based on the Boeing 737-700 and has seen 14 deliveries. This design comes with a wide array of radar antennas and radio technology for combat and weather needs.

Other Boeing Aircraft

The Boeing 747 has had two military variants over the years. The 1970s saw the birth of the Boeing E-4 mobile command center for the U.S. which was based on the Boeing 747-200. There are currently four E-4s in use and are under the control of the United States Strategic Air Command.

Boeing’s other 747 design was a laser test aircraft called the YAL-1. The airplane was trying to use lasers to stop and potential missile strikes that the U.S. might encounter. The project was stripped of it funding, and the one YAL-1 was sent to Davis-Monthan Air Force Base for parts.

The Boeing 767 has seen great amounts of use as an air refueler. The KC-767 was made in 2004 and saw orders from Italy, Japan, Colombia and Brazil, with the total coming down to 11 aircraft. The KC-767 features either one rear mounted boom or two looser booms on the wingtips. The KC-767 is still used by the four governments that ordered the aircraft.

Meanwhile, the KC-46 Pegasus is an advancement of the KC-767, with the aircraft increasing fuel capacity by 51,000 pounds of fuel. The aircraft will feature one rear mounted boom and is expected to enter service with the United States Air Force in 2018, replacing the Boeing KC-135 Stratotanker.

Although Ian McMurtry was never originally an avgeek, he did enjoy watching US Airways aircraft across western Pennsylvania in the early 2000s. He lived along the Pennsylvania Railroad and took a liking to trains but a change of scenery in the mid-2000s saw him shift more of an interest into aviation. He would eventually express this passion by taking flying lessons in mid-Missouri and joining AirlineGeeks in 2013. Now living in Wichita, Kansas, Ian is in college majoring in aerospace engineering and minoring in business administration at Wichita State University.